# Mulcahy (surname)

Source: https://namelineage.com/surname/mulcahy/  
Publisher: Name Lineage. Counts from the US Census Bureau; origin and etymology from Wiktionary; bearers from Wikidata. Data updated 2026-11-11.

A surname from Irish.

| Field | Value |
|---|---|
| Origin | Irish |
| Type | patronymic, formed from a father’s (or ancestor’s) given name |
| People in the US (2010 Census) | 6,595 |
| US rank (2010) | 5,279 of 162,253 |
| How often | about 1 in every 46,815 people |
| Change since 2000 | +2.3% (6,444 in 2000) |
| Pronunciation | /mʌlˈkæhiː/, 3 syllables |
| Variant spellings | Mulkey |

## Etymology

Reduced Anglicized form of Irish Ó Maolchathaigh (“descendant of the devotee of (Saint) Cathach”), a byname from cathachyss (“warlike”).

## Who carries it

Share of people named Mulcahy in the 2010 US Census by the Census's own race and ethnicity groups. The Census suppresses a share when the count behind it is small.

| Group | Share |
|---|---|
| White (not Hispanic) | 96% |
| Black (not Hispanic) | 0.1% |
| Hispanic or Latino (any race) | 2.2% |
| Asian and Pacific Islander | 0.6% |
| American Indian and Alaska Native | 0.2% |
| Two or more races | 1.1% |

## Where

Wikidata records people named Mulcahy in Australia and the United States.

## People named Mulcahy

- Russell Mulcahy, Australian film director
- John Mulcahy, American rower (1876–1942)

## Similar surnames

Mulkey, Mulcahey, Mills, Miles, Malik, Myles, Mullis, Mielke, Malek, Milazzo, Moles, Milewski.

## How to read these numbers

A Census count is people alive and counted in 2010, not births, and names occurring fewer than 100 times are not published at all. Ethnicity shares are the Census's own categories.